All tire constructions exhibit some inherent offsets in forces and moments, generically called pull forces. When the radial became the predominate tire construction, pull forces became a nuisance to tire and automotive manufacturers. Over the past four decades, the science has become essentially complete, but confusion still occurs and scientific work is repeated. This is partially because there is not a comprehensive reference uniting the existing information. This article is a comprehensive reference dealing with effects, measurement, sources, and how a frustrated service person can decide what is really going on within the context of a service facility.